1. Field of the Invention
The present invention relates to guards and safety guards for well drilling equipment, and more particularly relates to an improved kelly bushing guard which protectively covers a portion of the well drilling kelly, the kelly bushing guard, and the rotary table portions of the well drilling rig during drilling operations.
2. General Background and Prior Art
Various cage or casing type protective devices have been used to separate personal from machinery and related equipment utilized on off-shore and like well drilling rigs. These protective devices are generally stationery and are used to prevent personal from coming in contact with moving parts of machinery which could snag the individual or his clothing.
In well drilling operations such as is the case in oil well or gas well drilling operations, protective devices are of great value since machinery utilized has a tremendous amount energy and can mutilate or injure or kill personal who may become tangled or inadvertently contacted therewith.
Specifically, the well drilling rotary table, the well drilling kelly, and the kelly bushing are three such parts which at certain times in the drilling operation are moved and contain a tremendous amount of energy capable of inflicting injuries.
Several devices have been patented which have attempted to solve the problems of shielding dangerous machinery. Some of these devices have particular application to the oil field and to oil well drilling rigs and related devices.
The following table provides a listing of some prior art devices which have been patented.
______________________________________ Prior Art Patents U.S. Pat. No. Inventor Issue Date ______________________________________ 2,312,323 O. L. Derrick March 2, 1943 2,559,100 W. L. White July 3, 1951 2,592,633 J. H. Wilson April 15, 1952 2,719,025 A. L. Stone Sept. 27, 1955 2,730,333 W. E. Lenhart, Jr. Jan. 10, 1956 2,789,870 J. W. E. Hanes April 23, 1957 2,959,453 H. C. Jacobs Nov. 8, 1960 3,019,063 C. H. Collett Jan. 30, 1962 3,038,537 W. D. Brunig June 12, 1962 3,051,532 C. H. Collett Aug. 28, 1962 3,063,509 W. C. Guier Nov. 13, 1962 3,078,933 A. B. Orner Feb. 26, 1963 3,111,863 D. J. Filz Nov. 26, 1963 3,270,810 L. A. Johnston Sept. 6, 1966 3,322,198 W. L. McHenry May 30, 1967 3,612,627 L. E. Fuller Sept. 23, 1969 3,910,359 A. J. Childress Oct. 7, 1975 3,913,352 D. L. Oliver Oct. 4, 1973 459,065 German F. F. Stille Aug. 19, 1927 ______________________________________